A number of problems must be solved before semiconductor packages can be reduced in thickness to satisfy the recent needs in the art. For example, flat packages are mounted on printed circuit boards by immersing the packages in a hot solder bath. Exposure to thermal shocks often causes packages of conventional epoxy resin compositions to crack. It was recently pointed out that if packages had absorbed water prior to mounting on printed circuit boards, steam explosion could occur within the packages upon hot solder immersion, inducing cracks therein.
Countermeasures to these problems have been proposed by addressing to both the frame and the epoxy resin composition, but few are satisfactory. It is thus desired to improve the thermal impact and adherence of an epoxy resin composition.